SOME WOOD-BORING INSECTS 395 



but, in Washington, it has been carried through all of its 

 transformations in about three and one-half months. 

 The pupal period lasted thirteen days. 



The brown spider-beetle is often found associated with 

 the species just discussed. There is not the great differ- 

 ence between the sexes that we find in the white-marked 

 species. This species is widely distributed, having been 

 reported from Europe, Asia, and America. It is a more or 

 less serious pest to books. Leather-bound and sheep- 

 bound books seem to be their favorite food in the book line. 

 They usually bore galleries in the leather where it is joined 

 to the back of the leaves of the book. 



It is probable that there is little difference in the life 

 history and habits between this and the preceding species. 

 The larva? of this species have been found in feathers, fur, 

 dried mushrooms, in drugs, in the powdered leaves of 

 senna and Jaborandi and other materials. In fact, the 

 larvae live upon much the same material as the larvae of 

 the white-marked spider-beetle. 



METHODS OF CONTROLLING THESE SMALL BEETLES 



In the case of the powder-post beetles it may become 

 advantageous and, in fact, absolutely necessary to remove 

 the infested timbers and replace them with new ones. 

 This is especially true in case of those timbers that are 

 used to support heavy materials. Again, it should be 

 borne in mind that these beetles work only in sap wood. 

 It is therefore of advantage to use only heart wood in 

 construction, if it is possible to obtain it. 



In those instances where it is not possible to remove the 

 affected timbers, they may be treated to a thorough 



